ASoC: fsl: constify snd_pcm_ops structures

snd_pcm_ops are not supposed to change at runtime. All functions
working with snd_pcm_ops provided by <sound/soc.h> work with
const snd_pcm_ops. So mark the non-const structs as const.

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/fsl/fsl_dma.c

@@ -870,7 +870,7 @@ static struct device_node *find_ssi_node(struct device_node *dma_channel_np)
 	return NULL;
 }
 
-static struct snd_pcm_ops fsl_dma_ops = {
+static const struct snd_pcm_ops fsl_dma_ops = {
 	.open   	= fsl_dma_open,
 	.close  	= fsl_dma_close,
 	.ioctl  	= snd_pcm_lib_ioctl,